Device and method for vaporizing/discharging chemical agent

ABSTRACT

Provided is a chemical agent vaporizing/discharging device which can efficiently vaporize and discharge a chemical agent from a chemical agent retainer, and sufficiently diffuse the chemical agent, even when the device is used in a relatively large space or outdoors. A chemical agent vaporizing/discharging device 100 comprises: a chemical agent retainer 50 having a chemical agent retention layer 10 including interstices 11 for allowing retention of a volatile chemical agent, and a gas permeable layer 20 including voids 21 having a size larger than a size of the interstices 11; and a rotational drive part 60 for driving the chemical agent retainer 50. A shape and a size of the chemical agent retainer 50, and a rotational speed of the rotational drive part 60, are set so that a centrifugal effect of 10 to 150 (G) is obtained during rotation of the chemical agent retainer 50.

The present application is a U.S. National Stage Application based onand claiming benefit and priority under 35 U.S.C. § 371 of InternationalApplication No. PCT/JP2015/084873, filed 14 Dec. 2015, which in turnclaims benefit of and priority to Japanese Application No. 2014-253418filed 15 Dec. 2014, the entirety of both of which is hereby incorporatedherein by reference.

TECHNICAL FIELD

The present invention relates to methods and devices for vaporizing anddischarging a volatile chemical agent into the air.

BACKGROUND ART

In order to control insect pests, chemical agent vaporizing/dischargingdevices for vaporizing and discharging into space a chemical agentcapable of repelling or killing insect pests have been commercialized.For example, known is a device which retains a volatile chemical agentin a diffusion member (chemical agent retainer), and drives thediffusion member using a drive means to vaporize and discharge thechemical agent into the air (see, for example, Patent Document 1).Patent Document 1 indicates that the diffusion member is configured inthe shape of a fan in order to enhance the capability to vaporize anddischarge the chemical agent, and the diffusion member is heated inorder to vaporize and discharge a larger amount of the chemical agent.

Also known is the use of a honeycomb structure having multiple cellswith both open ends having a cell size of 2 to 5 mm as a chemical agentretention carrier (chemical agent retainer) (see, for example, PatentDocument 2). Patent Document 2 indicates that the honeycomb structureserving as a chemical agent retention carrier ensures a large area forretaining a chemical agent, and can reduce drag acting on a flow of airpassing through the chemical agent retention carrier.

CITATION LIST Patent Literature

Patent Document 1: Japanese Unexamined Patent Application PublicationNo. H05-68459

Patent Document 2: Japanese Unexamined Patent Application PublicationNo. H11-92303

SUMMARY OF INVENTION Technical Problem

Most chemical agent vaporizing/discharging devices are mainly usedindoors. Due to recent changes in housing, a space in which a chemicalagent vaporizing/discharging device is used tends to increase. There isan increasing demand for use of a chemical agent vaporizing/dischargingdevice not only in a living room etc. of a house, but also in arelatively large space such as an office, shop, workplace, or the like,and outdoors.

In this regard, the subject matter disclosed in Patent Document 1 andPatent Document 2 is not intended for use in a large space or outdoors.Patent Document 1 indicates that the chemical agent retainer is used ina space such as a living room of an ordinary house (see paragraph [0029]of Patent Document 1). Patent Document 2 indicates an example in whichthe chemical agent retainer was subjected to an insect pest control testin a living room having an area of six Jyos (Jyo is a Japanese unit ofarea: 1 Jyo is equal to about 1.7 m²) (see paragraph [0032] in PatentDocument 2). Thus, the subject matter disclosed in Patent Document 1 andPatent Document 2 is used in a living room of a typical house or thelike, and therefore, when it is used in a relatively large space oroutdoors, the effect of vaporizing and discharging a chemical agent maynot be sufficient.

With the above in mind, the present invention has been made. It is anobject of the present invention to provide a device and method forvaporizing and discharging a chemical agent which are capable ofefficiently vaporizing and discharging the chemical agent from achemical agent retainer, and sufficiently diffusing the chemical agent,even when it is used in a relatively large space or outdoors.

Solution to Problem

To achieve the above object, a chemical agent vaporizing/dischargingdevice according to the present invention comprises:

a chemical agent retainer having a chemical agent retention layerincluding interstices for allowing retention of a volatile chemicalagent, and a gas permeable layer including voids having a size largerthan a size of the interstices; and

a rotational drive part for driving the chemical agent retainer,

wherein

a shape and a size of the chemical agent retainer, and a rotationalspeed of the rotational drive part, are set so that a centrifugal effectof 10 to 150 (G) is obtained during rotation of the chemical agentretainer.

In order to increase the efficiency of vaporization and discharging of avolatile chemical agent in a chemical agent retainer, typically, thechemical agent retainer may be rotated to generate an air flow asdisclosed in Patent Document 1, or an air flow may be impinged on thechemical agent retainer using a fan as disclosed in Patent Document 2,or the like. In the conventional art, for example, in the case of PatentDocument 1, it is considered that a great centrifugal force needs to beexerted on the chemical agent retainer. However, according to theresults of recent study conducted by the present inventors, it is notalways necessary or effective to simply increase the speed of revolutionof the chemical agent retainer or the air blowing power, or increase thesize of the chemical agent retainer, and thereby increase a centrifugalforce exerted on the chemical agent retainer, in order to increase theefficiency of vaporization and discharging of a volatile chemical agentfrom a chemical agent retainer, and various settings should be made inorder to obtain a suitable centrifugal effect in the chemical agentretainer. This is why, in the present invention, the chemical agentvaporizing/discharging device has the above configuration.

In the chemical agent vaporizing/discharging device having this feature,the chemical agent retainer has a chemical agent retention layerincluding interstices for allowing retention of a volatile chemicalagent, and a gas permeable layer including voids having a size largerthan a size of the interstices. Therefore, the volatile chemical agentretained in the interstices of the chemical agent retention layer ismoved to the voids of the gas permeable layer, in which the chemicalagent is easily vaporized and discharged into the air. In this state,when the chemical agent retainer is rotated by the rotational drivepart, the volatile chemical agent is vaporized and discharged into theair. At this time, a shape and a size of the chemical agent retainer,and a rotational speed of the rotational drive part, are set so that acentrifugal effect of 10 to 150 (G) is obtained in the chemical agentretainer. Therefore, the volatile chemical agent retained in thechemical agent retainer is efficiently vaporized and discharged into theair, and sufficiently diffused. Therefore, even when the chemical agentvaporizing/discharging device having this configuration is used in arelatively large space or outdoors, the effect of the volatile chemicalagent can be sufficiently exerted.

In the chemical agent vaporizing/discharging device of the presentinvention,

the chemical agent retainer is preferably set so that the ratio (P=A/B)of a thickness (A) of the gas permeable layer to a thickness (B) of thechemical agent retention layer is more than 1.5 and not more than 50,and

the rotational speed of the rotational drive part is preferably set sothat a centrifugal vaporizing/discharging index (T=G/P) obtained bydividing the centrifugal effect (G) by the ratio (P) is more than 1.1and less than 22.

In the chemical agent vaporizing/discharging device having this feature,the ratio (P=A/B) of the thickness (A) of the gas permeable layer to thethickness (B) of the chemical agent retention layer in the chemicalagent retainer, and the centrifugal vaporizing/discharging index (T=G/P)in the rotational drive part, are set with respective suitable ranges.Therefore, the volatile chemical agent retained in the chemical agentretainer can be more efficiently vaporized and discharged andsufficiently diffused into the air. Therefore, even when the chemicalagent vaporizing/discharging device having this feature is used in arelatively large space or outdoors, the effect of the volatile chemicalagent can be reliably exerted.

In the chemical agent vaporizing/discharging device of the presentinvention,

the chemical agent retainer is preferably a laminate of the chemicalagent retention layer and the gas permeable layer, and the chemicalagent retention layer is preferably provided one or both sides of thegas permeable layer in a lamination direction.

In the chemical agent vaporizing/discharging device having this feature,a suitable laminate of the chemical agent retention layer and the gaspermeable layer forms the chemical agent retainer. Therefore, thevolatile chemical agent retained in the chemical agent retention layercan be efficiently vaporized and discharged into the air, andsufficiently diffused, while the gas permeability of the gas permeablelayer is maintained.

In the chemical agent vaporizing/discharging device of the presentinvention,

the chemical agent retainer preferably has a form maintenance layer formaintaining a form of the gas permeable layer, the form maintenancelayer being disposed adjacent to the gas permeable layer.

In the chemical agent vaporizing/discharging device having this feature,a form of the gas permeable layer is maintained by the form maintenancelayer provided adjacent to the gas permeable layer, and therefore, thegas permeability of the chemical agent retainer can be sufficientlyensured. Therefore, the chemical agent vaporizing/discharging device canbe used until substantially all the volatile chemical agent retained inthe chemical agent retainer is vaporized and discharged into the air,i.e. used up.

In the chemical agent vaporizing/discharging device of the presentinvention,

the chemical agent retainer is preferably in the shape of a discperpendicular to an axis of rotation.

In the chemical agent vaporizing/discharging device having this feature,the chemical agent retainer is in the shape of a disc perpendicular toan axis of rotation, i.e. the chemical agent retainer has a reducedthickness, and therefore, the chemical agent vaporizing/dischargingdevice has excellent portability.

In the chemical agent vaporizing/discharging device of the presentinvention,

the chemical agent retainer is preferably in the shape of a hollowcylinder parallel to an axis of rotation.

In the chemical agent vaporizing/discharging device having this feature,the chemical agent retainer is in the shape of a hollow cylinderparallel to an axis of rotation. Therefore, all points along the lengthdirection on the chemical agent retention layer are equidistant from theaxis of rotation, and therefore, substantially the same centrifugaleffect is exerted on the volatile chemical agent at every point on thechemical agent retention layer. As a result, the chemical agentvaporizing/discharging effect can be exerted substantially uniformly allthe way around the chemical agent retainer.

In the chemical agent vaporizing/discharging device of the presentinvention,

the chemical agent retainer is preferably housed in a rotating cartridgecoupled to the rotational drive part.

In the chemical agent vaporizing/discharging device having this feature,the chemical agent retainer is rotated by the rotational drive partwhile the chemical agent retainer is housed in the rotating cartridge.Therefore, the chemical agent retainer is inhibited from being deformedby a centrifugal force. As a result, variations in the centrifugaleffect during rotation of the chemical agent retainer can be reduced.

In the chemical agent vaporizing/discharging device of the presentinvention,

the volatile chemical agent preferably contains a pyrethroid compoundhaving a vapor pressure of 2×10⁻⁴ to 1×10⁻² mmHg at 30° C.

In the chemical agent vaporizing/discharging device having this feature,a pyrethroid compound having a suitable vapor pressure is used as thevolatile chemical agent. Therefore, the centrifugal effect of thechemical agent retainer allows the pyrethroid compound to be efficientlyvaporized and discharged into the air, and sufficiently diffused.

To achieve the above object, a chemical agent vaporizing/dischargingmethod according to the present invention is for vaporizing anddischarging a volatile chemical agent into the air by rotating achemical agent retainer retaining the volatile chemical agent. Themethod comprises:

a rotation adjustment step of adjusting a rotational speed of thechemical agent retainer to obtain a centrifugal effect of 10 to 150 (G).

In the chemical agent vaporizing/discharging method having this feature,excellent effects similar to those of the chemical agentvaporizing/discharging device of the present invention described abovecan be obtained.

Specifically, in the rotation adjustment step of adjusting therotational speed of the chemical agent retainer, a shape and a size ofthe chemical agent retainer, and a rotational speed of the rotationaldrive part, are set so that a centrifugal effect of 10 to 150 (G) isobtained in the chemical agent retainer. Therefore, the volatilechemical agent retained in the chemical agent retainer is efficientlyvaporized and discharged into the air, and sufficiently diffused.Therefore, even when the chemical agent vaporizing/discharging methodhaving this feature is used in a relatively large space or outdoors, theeffect of the volatile chemical agent can be sufficiently exerted.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a schematic perspective view of a chemical agent retainerwhich is used in a chemical agent vaporizing/discharging deviceaccording to the present invention.

FIG. 2 is a schematic diagram of a configuration of a chemical agentvaporizing/discharging device according to a first embodiment of thepresent invention.

FIG. 3 is a schematic diagram of a configuration of a chemical agentvaporizing/discharging device according to a second embodiment of thepresent invention.

DESCRIPTION OF EMBODIMENTS

Embodiments relating to a chemical agent vaporizing/discharging deviceaccording to the present invention will now be described. This isaccompanied by description of a chemical agent vaporizing/dischargingmethod according to the present invention. The present invention is inno way intended to be limited to configurations described in theembodiments below or the accompanying drawings.

A chemical agent vaporizing/discharging device according to the presentinvention comprises, as basic components, a chemical agent retainer anda rotational drive part. For the sake of convenience, the chemical agentretainer, and a volatile chemical agent retained in the chemical agentretainer, will be first described, and thereafter, a chemical agentvaporizing/discharging device according to the present invention will bedescribed.

(Chemical Agent Retainer)

FIG. 1 is a schematic perspective view of a chemical agent retainer 50which is used in a chemical agent vaporizing/discharging deviceaccording to the present invention. In FIG. 1, a larger circle is anenlarged view of a portion of a facet of the chemical agent retainer 50,which is a laminate. The chemical agent retainer 50 comprises a chemicalagent retention layer 10 and a gas permeable layer 20, and a formmaintenance layer 30 as an optional component. The chemical agentretention layer 10 has interstices 11 which can retain a volatilechemical agent described below. The interstices 11 in the chemical agentretention layer 10 can draw up and retain the volatile chemical agent bycapillary action. The gas permeable layer 20 has voids 21 through whichair can flow. The voids 21 in the gas permeable layer 20 have a largersize than a size of the interstices 11 in the chemical agent retentionlayer 10. Therefore, if the volatile chemical agent retained in theinterstices 11 of the chemical agent retention layer 10 is moved to thevoids 21 of the gas permeable layer 20, the volatile chemical agent canbe easily vaporized and discharged into the air.

The chemical agent retention layer 10 and the gas permeable layer 20preferably include a fibrous structure such as a mesh fiber sheet, wovenfabric, nonwoven fabric, knitting, or the like, or alternatively, mayinclude a porous material such as a porous sheet, porous film, or thelike. The chemical agent retention layer 10 and the gas permeable layer20 may be made of either the same or different materials. When thechemical agent retention layer 10 and the gas permeable layer 20 aremade of the same material, the chemical agent retention layer 10 havingthe interstices 11 and the gas permeable layer 20 having the voids 21which are made of the same material are separately prepared and thenjoined together to form the chemical agent retainer 50. Alternatively,the chemical agent retention layer 10 and the gas permeable layer 20 maybe formed as an integrated fibrous structure or porous structure inwhich fiber interstices in the fibrous structure or pores in the porousstructure are larger in the gas permeable layer 20 than in the chemicalagent retention layer 10, in a stepwise or gradient fashion. If thechemical agent retention layer 10 and the gas permeable layer 20 aremade of different materials, the chemical agent retention layer 10 ismade of a woven fabric, and the gas permeable layer 20 is made of a meshfiber sheet, and these layers are joined together to provide a fibrousstructure, for example. In this case, fibers used in the chemical agentretention layer 10 and the gas permeable layer 20 are selected frommaterials which can stably vaporize and discharge the volatile chemicalagent retained therein, and satisfactorily sustain the state of thevaporization and discharging. Examples of such a material (fiber) forthe fibrous structure include: natural fibers, such as cotton, hemp,wool, silk, and the like; semisynthetic fibers, such as rayon and thelike; synthetic fibers, such as polyesters (polyethyleneterephthalate,polybutyleneterephthalate, etc.), nylon, acrylic, vinylon, polyethylene,polypropylene, aramid, polyphenylene sulfide, and the like; andinorganic fibers, such as glass fiber, carbon fiber, ceramic fiber,metal fiber, and the like. Of these fibers, polyester and nylon arepreferably used. These fibers may be used alone or in combination.

Note that when the chemical agent retention layer 10 and the gaspermeable layer 20 are put on top of each other to form the chemicalagent retainer 50, the chemical agent retention layer 10 may be providedon one side of the gas permeable layer 20 in the lamination direction asshown FIG. 1, or alternatively, the chemical agent retention layer 10may be provided on both sides of the gas permeable layer 20. Stillalternatively, the chemical agent retention layer 10 and the gaspermeable layer 20 may be arranged in alternate layers in this order toform a structure having three or more layers. Furthermore, as long asthe chemical agent retention capability or strength of the chemicalagent retention layer 10 is not impaired, the chemical agent retentionlayer 10 may be suitably perforated to have air holes so that thechemical agent vaporizing/discharging performance can be improved.

Incidentally, when the gas permeable layer 20 of the chemical agentretainer 50 has a fibrous structure including a three-dimensional meshfiber sheet or the like, fiber interstices (the void 21) in the gaspermeable layer 20 should be robust in order to ensure good gaspermeability of the chemical agent retainer 50. To this end, in thechemical agent retainer 50, as shown in FIG. 1, the form maintenancelayer 30 is preferably provided adjacent to the gas permeable layer 20.The form maintenance layer 30 is interwoven with fibers included in thegas permeable layer 20, and thereby functions to maintain the voids 21of the gas permeable layer 20. Therefore, a sufficient gas permeabilityof the chemical agent retainer 50 can be ensured. As a result,substantially all the volatile chemical agent retained in the chemicalagent retainer 50 can be vaporized and discharged into the air, i.e. canbe used up. Note that the gas permeability of the material for thechemical agent retainer 50 is preferably set within the range of 200 to500 cm³/cm²/sec as measured in accordance with Japanese IndustrialStandards (JIS L 1096). If the degree of the gas permeability of thematerial falls within the above range, capillary action is preferablyenhanced, so that the volatile chemical agent moves smoothly, leading toefficient vaporization and discharging.

The chemical agent retention layer 10 and the gas permeable layer 20,and the form maintenance layer 30 as an optional component, included inthe chemical agent retainer 50, are set to respective suitablethicknesses. The thickness of the chemical agent retention layer 10 isset to 0.05 to 3 mm, preferably 0.2 to 1 mm. If the thickness of thechemical agent retention layer 10 is less than 0.05 mm, the chemicalagent retention layer 10 does not have a sufficient capacity to retainthe volatile chemical agent, and therefore, has difficulty insufficiently and sustainably exerting the effect of the volatilechemical agent. If the thickness of the chemical agent retention layer10 is more than 3 mm, the chemical agent retention layer 10 has anexcessive retention capability of the volatile chemical agent, so that aportion of the volatile chemical agent remains in the chemical agentretention layer 10, and therefore, it is difficult to efficientlyvaporize and discharge the volatile chemical agent. In addition, thechemical agent retention layer 10 has a large volume, and therefore, itis difficult to form the chemical agent retention layer 10 into variousshapes. The gas permeable layer 20 is set to 0.5 to 6 mm, preferably 1to 5 mm. If the thickness of the gas permeable layer 20 is less than 0.5mm, the gas permeable layer 20 is excessively humidified with thevolatile chemical agent, and an air flow force (stirred air flow) causedby the gas permeable layer is weak, and therefore, it is difficult toefficiently vaporize and discharge the volatile chemical agent. If thethickness of the gas permeable layer 20 is more than 6 mm, the thicknessof the chemical agent retention layer 10 should be reduced due to thethickness constraint of the chemical agent retainer 50, and as a result,the chemical agent retention capability of the chemical agent retainer50 is likely to be impaired, or air flow drag caused by the gaspermeable layer 20 is likely to increase, leading to unstablevaporization and discharging of the volatile chemical agent. The formmaintenance layer 30 is set to 0.2 to 1 mm. When the thickness of theform maintenance layer 30 falls within this range, the form of thechemical agent retainer 50 can be maintained over a long period of timewhile the gas permeability of the chemical agent retainer 50 is ensured.

(Volatile Chemical Agent)

The volatile chemical agent retained in the chemical agent retainer 50may be any chemical agent that has a suitable volatility at roomtemperature. The amount of the volatile chemical agent retained in thechemical agent retainer 50 is adjustable within the range of 40 to 2000mg, depending on conditions such as an application thereof, a period oftime during which the activity should be sustained, and the like.Examples of a volatile chemical agent which can be used in the presentinvention include volatile pyrethroid compounds, insecticides,acaricides, repellents, antimicrobials, insect repellent aromachemicals, deodorants, and the like. Of these agents, volatilepyrethroid compounds are a volatile chemical agent having an excellentinsect repelling effect and insect killing effect, and therefore, arepreferably used. In particular, a pyrethroid compound having a vaporpressure of 2×10⁻⁴ to 1×10⁻² mmHg at 30° C. has a good balance betweenvolatility and sustainability, and therefore, is more preferably used.Examples of a useful volatile pyrethroid compound include2,3,5,6-tetrafluorobenzyl 2,2-dimethyl-3-(2,2-dichlorovinyl)cyclopropanecarboxylate (transfluthrin), 4-methyl-2,3,5,6-tetrafluorobenzyl2,2-dimethyl-3-(1-propenyl)cyclopropane carboxylate (profluthrin),4-methoxymethyl-2,3,5,6-tetrafluorobenzyl2,2-dimethyl-3-(1-propenyl)cyclopropane carboxylate (metofluthrin),4-methoxymethyl-2,3,5,6-tetrafluorobenzyl2,2,3,3-tetramethylcyclopropane carboxylate,4-propargyl-2,3,5,6-tetrafluorobenzyl 2,2,3,3-tetramethylcyclopropanecarboxylate, empenthrin, and the like. Some of these pyrethroidcompounds have various isomers. In this case, one of the isomers may beused alone, or a mixture containing some or all of the isomers at anysuitable ratio may be used. Two or more of the above pyrethroidcompounds may be suitably selected and their volatilities may beadjusted to provide a formulation which can be used for a long period oftime.

Examples of insecticides as a volatile chemical agent other than theabove pyrethroid compounds, include neonicotinoid insecticidalingredients, such as dinotefuran and the like, organic phosphorusinsecticidal ingredients, such as fenitrothion and the like, andcarbamate insecticidal ingredients, such as propoxur and the like.Examples of acaricides include 5-chloro-2-trifluoromethanesulfonamidemethyl benzoate, phenyl salicylate, 3-iodo-2-propynylbutyl carbamate,and the like. Examples of repellents (repelling ingredients) includeDEET, dimethyl phthalate, 2-ethyl-1,3-hexanediol, and the like. Examplesof antimicrobials (antimicrobial ingredients) include hinokitiol,tetrahydrolinalool, eugenol, allyl isothiocyanate, and the like.Examples of insect repellent aroma chemicals include citronella oil,orange oil, lemon oil, lime oil, yuzu oil, lavender oil, peppermint oil,eucalyptus oil, jasmine oil, cypress oil, green tea essential oil,limonene, α-pinene, citronellal, terpineol, linalool, geraniol,phenylethyl alcohol, amylcinnamic aldehyde, cuminaldehyde, benzylacetate, and the like. In addition to deodorants, it is useful to blenda leaf alcohol or leaf aldehyde called “fragrance of green.”

The volatile chemical agent may be used directly, or alternatively, maybe diluted with various solvents, or may be blended with variousadditives. Examples of such a solvent include hydrocarbon solvents, suchas n-paraffin, isoparaffin, and the like, glycols having 3 to 6 carbonatoms, such as propylene glycol, 1,3-butylene glycol, 1,4-butyleneglycol, diethylene glycol, dipropylene glycol, hexylene glycol, and thelike, glycol ethers, ketone solvents, ester solvents, and the like. Thevolatile chemical agent is suitably diluted using these solvents, andthe resultant dilution is retained in the chemical agent retainer 50.Examples of the additives include stabilizers, such as BHT, BHA,2,2′-methylene bis(4-ethyl-6-t-butylphenol), 2,2′-methylenebis(4-methyl-6-t-butylphenol), 4,4′-methylenebis(2-methyl-6-t-butylphenol), 3,5-di-t-butyl-4-hydroxyanisole,mercaptobenzimidazole, and the like. Various ingredients may beoptionally added, such as a UV absorber, UV scattering agent,brightening agent, anti-inflammatory agent, antiperspirant, moisturizer,surfactant, dispersant, aroma chemical, and the like.

(Chemical Agent Vaporizing/Discharging Device)

Next, a chemical agent vaporizing/discharging device according to thepresent invention which comprises the above chemical agent retainer willbe described. The chemical agent vaporizing/discharging device of thepresent invention is used to vaporize and discharge a volatile chemicalagent such as an insecticide, repellent, or the like, into the air inorder to control flying insect pests, such as mosquitoes, nonbitingmidges, small flies, and the like, and creeping insect pests, such ascockroaches, ants, centipedes, spiders, and the like. Two representativeexamples of the chemical agent vaporizing/discharging device of thepresent invention will now be described.

First Embodiment

FIG. 2 is a schematic diagram of a configuration of a chemical agentvaporizing/discharging device 100 according to a first embodiment of thepresent invention. FIG. 2(a) is a vertical cross-sectional view of thechemical agent vaporizing/discharging device 100. FIG. 2(b) is ahorizontal cross-sectional view of the chemical agentvaporizing/discharging device 100 taken along line A-A′ of FIG. 2(a).The chemical agent vaporizing/discharging device 100 comprises, as basiccomponents, a chemical agent retainer 51 and a rotational drive part 60.The chemical agent retainer 51 is a laminate of a chemical agentretention layer 10 and a gas permeable layer 20. A form maintenancelayer 30 is provided adjacent to the gas permeable layer 20. In thechemical agent vaporizing/discharging device 100 of this embodiment, thechemical agent retainer 51 is formed in the shape of a disc as shown inFIG. 2(b). Specifically, the chemical agent retainer 50 which is alaminate sheet of the chemical agent retention layer 10, the gaspermeable layer 20, and the form maintenance layer 30 shown in FIG. 1 isdie-cut into a circular shape. In this case, the size of the chemicalagent retainer 51 is set as follows: the diameter R1 of the chemicalagent retainer 51 is about 4 to 8 cm; and the thickness D1 of thelaminate of the chemical agent retention layer 10 and the gas permeablelayer 20 is about 1 to 7 mm. Such a disc shape allows a reduction in thethickness of the chemical agent retainer 51, and therefore, excellentportability can be imparted to the chemical agent vaporizing/dischargingdevice 100.

The disc-shaped chemical agent retainer 51 is housed in a rotatingcartridge 70 in use. The rotating cartridge 70 comprises a shaft 71 anda case 72. The chemical agent retainer 51 is fixed to the shaft 71 withthe shaft 71 penetrating through a center of the chemical agent retainer51. The case 72 of the rotating cartridge 70 is provided with a suitableopening (not shown) so that a volatile chemical agent is efficientlyvaporized and discharged from the chemical agent retainer 51. The shaft71 of the rotating cartridge 70 is coupled to the rotational drive part60. The rotational drive part 60, which includes a power supply 61 and adrive motor 62, can rotate the rotating cartridge 70 housing thechemical agent retainer 51 at a predetermined rotational speed. Thus,when the chemical agent retainer 51 housed in the rotating cartridge 70is rotated by the rotational drive part 60, the chemical agent retainer51 is inhibited from being deformed by a centrifugal force, andtherefore, variations in a centrifugal effect (described below) duringrotation of the chemical agent retainer 51 can be reduced. The powersupply 61 of the rotational drive part 60 may be either a direct currentpower supply or an alternating current power supply. When the chemicalagent vaporizing/discharging device 100 is carried, a battery ispreferably used, such as an alkaline battery, zinc-carbon battery,rechargeable battery, solar battery, or the like. The capacity of thebattery may be suitably selected according to usage or dosage. Forexample, when the chemical agent vaporizing/discharging device 100 isused as a portable or indoor vaporizing/discharging device, a C, AA, orAAA battery is preferably used. When the chemical agentvaporizing/discharging device 100 is used as a large-scalevaporizing/discharging device for a large space, a plurality of D or Cbatteries are preferably used. The drive motor 62 may be any commonlyused motor, such as, for example, a brushed motor or brushless motor. Inparticular, brushless motors are excellently durable and usable, andtherefore, are suitably used as the drive motor 62 of the chemical agentvaporizing/discharging device 100. The speed of revolution of the drivemotor 62 (i.e., the speed of revolution of the chemical agent retainer51) is set to 500 to 2000 rpm, preferably 700 to 1600 rpm. If the speedof revolution is less than 500 rpm, the chemical agentvaporizing/discharging effect is less likely to be sufficient. If thespeed of revolution is more than 2000 rpm, then when a battery is usedas the power supply 61, charge is more quickly consumed, and therefore,the chemical agent vaporizing/discharging device 100 cannot performlong-term operation. The rotational drive part 60 may be provided withan on-off switch, a pilot light or the like for indicating the end ofoperation, or the like. If a pilot light or the like is provided, thesurface temperature of the rotational drive part 60 is slightlyincreased due to heat generation, and therefore, by utilizing the heat,the vaporization of the volatile chemical agent retained in the chemicalagent retainer 51 can be enhanced.

When the rotational drive part 60 is driven, the chemical agent retainer51 and the rotating cartridge 70 are rotated, as an integratedstructure, around the shaft center (axis of rotation) X of the shaft 71.At this time, a centrifugal force is exerted on the chemical agentretainer 51 due to the rotation, which is accompanied by a stirred airflow occurring around the chemical agent retainer 51 as indicated byarrows in FIG. 2(a). As a result, the volatile chemical agent retainedin the chemical agent retention layer 10 is vaporized and dischargedfrom the gas permeable layer 20 into the air, and is further diffused,so that an insect repelling effect and an insect killing effect areexerted around the chemical agent vaporizing/discharging device 100.

Second Embodiment

FIG. 3 is a schematic diagram of a configuration of a chemical agentvaporizing/discharging device 200 according to a second embodiment ofthe present invention. FIG. 3(a) is a vertical cross-sectional view ofthe chemical agent vaporizing/discharging device 200. FIG. 3(b) is ahorizontal cross-sectional view of the chemical agentvaporizing/discharging device 200 taken along line B-B′ of FIG. 3(a).The chemical agent vaporizing/discharging device 200 comprises, as basiccomponents, a chemical agent retainer 52 and a rotational drive part 60,as with the chemical agent vaporizing/discharging device 100 of thefirst embodiment. The chemical agent retainer 52 is a laminate of achemical agent retention layer 10 and a gas permeable layer 20. A formmaintenance layer 30 is provided adjacent to the gas permeable layer 20.In the chemical agent vaporizing/discharging device 200 of thisembodiment, the chemical agent retainer 52 is formed in the shape of ahollow cylinder as shown in FIG. 3(b). Specifically, to provide thisform, the sheet-shaped chemical agent retainer 50 of FIG. 1, which is alaminate of the chemical agent retention layer 10, the gas permeablelayer 20, and the form maintenance layer 30, is rolled into acylindrical shape with the chemical agent retention layer 10 facinginward. In this case, the size of the chemical agent retainer 52 is setas follows: the inner diameter R2 of the chemical agent retainer 52 isabout 6 to 10 cm; the thickness D2 of the laminate of the chemical agentretention layer 10 and the gas permeable layer 20 is about 1 to 7 mm;and the height T1 of the chemical agent retainer 52 is 3 to 10 cm,respectively. In such a hollow cylindrical chemical agent retainer 52,all points along the length direction on the chemical agent retentionlayer 10 are equidistant from the center axis (axis of rotationdescribed below), and therefore, substantially the same centrifugaleffect (described below) is exerted on the volatile chemical agent atevery point on the chemical agent retention layer 10. As a result, thechemical agent vaporizing/discharging effect can be exertedsubstantially uniformly all the way around the chemical agent retainer52.

The hollow cylindrical chemical agent retainer 52 is housed in arotating cartridge 70 in use. The rotating cartridge 70 comprises ashaft 71, a case 72, and a holding piece 73. The chemical agent retainer52 is inserted and fixed between the case 72 and the holding piece 73.The case 72 of the rotating cartridge 70 is provided with a suitableopening (not shown) in order to efficiently vaporize and discharge thevolatile chemical agent from the chemical agent retainer 52. The shaft71 of the rotating cartridge 70 is coupled to the rotational drive part60, which includes a power supply 61 and a drive motor 62. Therotational drive part 60 has a similar configuration to that of thefirst embodiment, which will not be described in detail.

When the rotational drive part 60 is driven, the chemical agent retainer52 and the rotating cartridge 70 are rotated, as an integratedstructure, around the shaft center (axis of rotation) X of the shaft 71.At this time, a centrifugal force is exerted on the chemical agentretainer 52 due to the rotation, which is accompanied by a stirred airflow occurring around the chemical agent retainer 52 as indicated byarrows in FIG. 3(a). As a result, the volatile chemical agent retainedin the chemical agent retention layer 10 is vaporized and dischargedfrom the gas permeable layer 20 into the air, and is further diffused,so that an insect repelling effect and an insect killing effect areexerted around the chemical agent vaporizing/discharging device 200.

(Centrifugal Effect in Chemical Agent Vaporizing/Discharging Device)

In the chemical agent vaporizing/discharging device 100 of the firstembodiment and the chemical agent vaporizing/discharging device 200 ofthe second embodiment, settings are made to obtain a suitablecentrifugal effect during rotation of the chemical agent retainer 50(51, 52). Here, the centrifugal effect (G) is an index which indicatesthe strength of a centrifugal force exerted on a rotating object, andhas a numerical value (G=m/sec²) represented by:Centrifugal effect (G)=R×N ²/894  (I)

(R: the radius of rotation (m), N: the speed of revolution (rpm))

The present inventors have found that when the shape and size of thechemical agent retainer 50 (51, 52) are set, and furthermore, therotational speed of the rotational drive part 60 is adjusted so that acentrifugal effect of 10 to 150 (G) is obtained during rotation of thechemical agent retainer 50 (51, 52), the volatile chemical agent can beefficiently vaporized and discharged from the chemical agent retainer 50(51, 52), and sufficiently diffused. If the centrifugal effect is lessthan 10 (G), the vaporizing/discharging performance of the chemicalagent vaporizing/discharging device 100, 200 is less likely to besufficient, and therefore, the insect repelling effect and insectkilling effect of the volatile chemical agent are less likely to besufficient. If the centrifugal effect is more than 150 (G), the volatilechemical agent retained in the chemical agent retainer 50 (51, 52) islikely to be scattered to surroundings, and therefore, the insectrepelling effect and insect killing effect are less likely to besufficient. Furthermore, the volatile chemical agent in liquid form maybe scattered so that surroundings become dirty. When the chemical agentvaporizing/discharging device 100, 200 is used to carry out the chemicalagent vaporizing/discharging method of the present invention, then ifthe rotational speed of the chemical agent retainer 50 (51, 52) isadjusted so that a centrifugal effect of 10 to 150 (G) is obtained(rotation adjustment step), the volatile chemical agent retained in thechemical agent retainer 50 (51, 52) can be efficiently vaporized anddischarged into the air, and sufficiently diffused. Therefore, even whenthe chemical agent vaporizing/discharging device 100, 200 is used in arelatively large space or outdoors, the insect repelling effect andinsect killing effect can be sufficiently exerted.

As to the vaporizing/discharging performance of the chemical agentvaporizing/discharging device 100, 200, the voids 21 of the gaspermeable layer 20 are set to a size larger than a size of theinterstices 11 of the chemical agent retention layer 10. Therefore, astirred air flow occurring due to rotation of the chemical agentretainer 50 (51, 52) may affect vaporization and discharging of thevolatile chemical agent. The present inventors have further extensivelystudied to find that if the thickness ratio of the chemical agentretention layer 10 and the gas permeable layer 20 included in thechemical agent retainer 50 (51, 52) is set to a suitable value withinthe range which allows the above centrifugal effect (G), the chemicalagent vaporizing/discharging device 100, 200 can efficiently exert thevaporizing/discharging performance. Here, the thickness ratio (P){P=A/B} of the gas permeable layer 20 and the chemical agent retentionlayer 10 is preferably set to more than 1.5 and not more than 50, whereA represents the thickness of the gas permeable layer 20, and Brepresents the thickness of the chemical agent retention layer 10. Ifthe thickness ratio (P) is not more than 1.5, the thickness (A) of thegas permeable layer 20 is insufficient with respect to the thickness (B)of the chemical agent retention layer 10, and therefore, the volatilechemical agent retained in the chemical agent retention layer 10 is lesslikely to be stably vaporized and discharged. Furthermore, a stirred airflow caused by the gas permeable layer 20 becomes weak, and therefore,the efficiency of vaporization and discharging of the volatile chemicalagent is reduced. Meanwhile, if the thickness ratio (P) is more than 50,the thickness (A) of the gas permeable layer 20 is excessively largewith respect to the thickness (B) of the chemical agent retention layer10, so that most of the volatile chemical agent retained in the chemicalagent retention layer 10 is quickly vaporized and discharged, andtherefore, the sustained effect of the volatile chemical agent is lesslikely to be obtained. When the chemical agent retainer 50 (51, 52) ishoused in the rotating cartridge 70, there is a constraint on the sum ofthe thicknesses of the chemical agent retention layer 10 and the gaspermeable layer 20, and therefore, the thickness of the chemical agentretention layer 10 is relatively small. As a result, the amount of thevolatile chemical agent retained is reduced, and therefore, the effectof the volatile chemical agent is less likely to be exerted for a longperiod of time.

Furthermore, the present inventors have closely studied a relationshipbetween the centrifugal effect (G) and the thickness ratio (P) to findthat if a centrifugal vaporizing/discharging index (T) is set within asuitable range, taking into consideration factors such as a rotationalload and the like, where the centrifugal vaporizing/discharging index(T) is a value (G/P) obtained by dividing the centrifugal effect (G) bythe thickness ratio (P), the chemical agent vaporizing/dischargingdevice 100, 200 can more efficiently exert the vaporizing/dischargingperformance. The present invention is effective when the rotationalspeed (i.e., the speed of revolution of the rotational drive part 60) ofthe chemical agent retainer 50 (51, 52) is set so that the centrifugalvaporizing/discharging index (T) is more than 1.1 and less than 22. Inthis case, the volatile chemical agent retained in the chemical agentretainer 50 (51, 52) is more efficiently vaporized and discharged, andsufficiently diffused in the air. Therefore, even when the chemicalagent vaporizing/discharging device 100, 200 is used in a larger spaceor outdoors, the insect repelling effect and insect killing effect canbe reliably exerted.

Note that, in the chemical agent vaporizing/discharging device 200 ofthe second embodiment, the chemical agent retainer 52 has a hollowcylindrical shape, and therefore, compared to the disc-shaped chemicalagent retainer 51 of the first embodiment, has a larger size and tendsto receive a greater rotational load. Meanwhile, the chemical agentretention layer 10 can have a larger surface area in the hollowcylindrical chemical agent retainer 52 than in the disc-shaped chemicalagent retainer 51. Therefore, in the second embodiment, the thickness ofthe chemical agent retention layer 10 may be reduced so that an increasein rotational load is canceled.

EXAMPLES

In order to verify the insect repelling effect and the insect killingeffect when the chemical agent vaporizing/discharging device of thepresent invention is used, outdoor effect verification tests (Examples1, 2, and 3) and indoor effect verification tests (Examples 4 and 5)were conducted.

Example 1

A chemical agent retention layer including polyester fibers (thickness:0.3 mm) and a gas permeable layer including polyester fibers (thickness:1.6 mm) were joined together into a laminate using twisted polyesterfibers, and a form maintenance layer (thickness: 0.2 mm) includingpolyester fibers was provided adjacent to and on top of the gaspermeable layer, to form a disc-shaped chemical agent retainer(thickness: 2.1 mm, outer diameter: 4.5 cm). In the chemical agentretainer, the thickness ratio (P) of the gas permeable layer and thechemical agent retention layer is 5.3. Next, the chemical agent retainerwas housed in a rotating cartridge made of polycarbonate (thickness: 8mm, outer diameter: 5.2 cm). A chemical liquid obtained by dissolving 40mg of metofluthrin in 0.07 mL of kerosene was dropped, as a volatilechemical agent, throughout the chemical agent retainer, so thatmetofluthrin was retained in the chemical agent retainer. Thereafter,the rotating cartridge was coupled to the rotational drive part. Achemical agent vaporizing/discharging device of Example 1 was thusconfigured.

In the chemical agent vaporizing/discharging device of Example 1, whenthe rotational drive part was rotated at 1200 rpm (in this case, thechemical agent retainer was also rotated at 1200 rpm), the centrifugaleffect (G) exerted on the chemical agent retainer was 36.2 (G), and thecentrifugal vaporizing/discharging index (T) obtained by dividing thecentrifugal effect (G) by the thickness ratio (P) was 6.8. When thechemical agent vaporizing/discharging device was attached to the waistof a subject, and was carried by the subject outdoors for a total of 120hours while the rotational drive part was rotating, the subject was notannoyed by unpleasant insect pests such as mosquitoes and the likeduring the test. Thus, for the chemical agent vaporizing/dischargingdevice of Example 1, an excellent insect repelling effect caused byvaporization and discharging of the volatile chemical agent wasverified.

Example 2

Two of the disc-shaped chemical agent retainers formed in Example 1 wereput on top of each other, and were housed in the same polycarbonaterotating cartridge as that of Example 1. A chemical liquid obtained bydissolving 60 mg of metofluthrin in 0.08 mL of kerosene was dropped, asa volatile chemical agent, throughout the chemical agent retainer, sothat metofluthrin was retained in the chemical agent retainer.Thereafter, the rotating cartridge was coupled to the rotational drivepart. A chemical agent vaporizing/discharging device of Example 2 wasthus configured.

The chemical agent vaporizing/discharging device of Example 2 wasoperated in a manner similar to that in Example 1. As a result, theinsect repelling effect was effective over 240 hours.

Example 3

A plate-like three-dimensional fiber structure including polyesterfibers (thickness: 4.5 mm) was directly used as a chemical agentretainer. Therefore, in the chemical agent retainer, a chemical agentretention layer (thickness: 0.3 mm), a gas permeable layer (thickness:3.9 mm), and a form maintenance layer (thickness: 0.3 mm) wereintegrally formed. In the chemical agent retainer, the thickness ratio(P) of the gas permeable layer and the chemical agent retention layerwas 13. Next, a chemical liquid obtained by dissolving 1.2 g oftransfluthrin in 1.2 mL of kerosene was dropped, as a volatile chemicalagent, throughout the chemical agent retainer, so that transfluthrin wasretained in the chemical agent retainer. Thereafter, the chemical agentretainer was rolled into a cylinder so that a hollow cylindrical shapewas formed. The resultant structure was housed in a polycarbonaterotating cartridge (diameter: 8 cm, height: 5 cm). Thereafter, therotating cartridge was coupled to the rotational drive part. A chemicalagent vaporizing/discharging device of Example 3 was thus configured.

In the chemical agent vaporizing/discharging device of Example 3, whenthe rotational drive part was rotated at 1000 rpm (in this case, thechemical agent retainer was also rotated at 1000 rpm), the centrifugaleffect (G) exerted on the chemical agent retainer was 44.7 (G), and thecentrifugal vaporizing/discharging index (T) obtained by dividing thecentrifugal effect (G) by the thickness ratio (P) was 3.4. The chemicalagent vaporizing/discharging device was placed outdoors while therotational drive part was rotating, and was used for a total of 960hours. Substantially no flying insect pests such as mosquitoes and thelike entered the range of about 5 m around the chemical agentvaporizing/discharging device during the test. Thus, for the chemicalagent vaporizing/discharging device of Example 3, an excellent insectrepelling effect caused by vaporization and discharging of the volatilechemical agent was verified.

Example 4

A disc-shaped chemical agent retainer retaining a volatile chemicalagent was formed using a procedure similar to that of Example 1, and washoused in a polycarbonate rotating cartridge similar to that ofExample 1. The rotating cartridge was coupled to a rotational drivepart. A chemical agent vaporizing/discharging device of Example 4 wasthus configured. Note that the chemical agent vaporizing/dischargingdevice of Example 4 was designed for 240-hour use, and therefore, thethickness of the disc-shaped chemical agent retainer was about two timesas large as the thickness of Example 1, and the amount of metofluthrinas the volatile chemical agent was 60 mg per chemical agent retainer. InExample 4, a plurality of chemical agent retainers having differentdiameters (R1) and different thickness ratios (P) of the gas permeablelayer and the chemical agent retention layer were prepared. By changingthe speed of revolution (N), centrifugal effect (G), and centrifugalvaporizing/discharging index (T) of the chemical agent retainer,differences in the effect of the volatile chemical agent were studied(test nos. 1 to 41 in Table 1). Specifically, the chemical agentvaporizing/discharging devices of test nos. 1 to 41 were each placed ata center of a room having an area of 6 Jyos (25 m³) in which 100 femaleadults of Culex pipiens were released, and an insect killing effectcaused by the volatile chemical agent was verified. The insect killingeffect was evaluated using KT50. A case where the time it took to knockdown 50% of the Culex pipiens mosquitoes was not less than 5 min andless than 30 min is indicated by a double circle. A case where such atime was not less than 30 min and less than 60 min is indicated by asingle circle. A case where such a time was not less than 60 min andless than 90 min is indicated by a triangle. A case where such a timewas not less than 90 min is indicated by a cross.

TABLE 1 Diameter Speed of Centrifugal Thickness ratio (P): CentrifugalInsect Test (R1) revolution (N) effect (G) {gas permeable layer (A)/vaporizing/discharging killing no. (cm) (rpm) (m/s²) chemical agentretention layer (B)} index (T): (G/P) effect 1 4.0 500 5.6 X 2 700 11.019 (3.8 mm/0.2 mm)  0.57 Δ 3 7 (3.5 mm/0.5 mm) 1.57 ◯ 4 3 (3.0 mm/1.0mm) 3.67 ◯ 5 1200 32.2 19 (3.8 mm/0.2 mm)  1.69 ◯ 6 7 (3.5 mm/0.5 mm)4.60 ⊚ 7 3 (3.0 mm/1.0 mm) 10.7 ⊚ 8 1600 57.3 19 (3.8 mm/0.2 mm)  3.02 ⊚9 7 (3.5 mm/0.5 mm) 8.19 ⊚ 10 3 (3.0 mm/1.0 mm) 19.1 ◯ 11 2000 89.5 19(3.8 mm/0.2 mm)  4.71 ◯ 12 7 (3.5 mm/0.5 mm) 12.8 ◯ 13 3 (3.0 mm/1.0 mm)29.8 Δ 14 6.0 500 8.4 X 15 700 16.4 19 (3.8 mm/0.2 mm)  0.86 Δ 16 7 (3.5mm/0.5 mm) 2.34 ◯ 17 3 (3.0 mm/1.0 mm) 5.47 ⊚ 18 1200 48.3  79 (3.95mm/0.05 mm) 0.62 — 19 19 (3.8 mm/0.2 mm)  2.54 ⊚ 20 7 (3.5 mm/0.5 mm)6.90 ⊚ 21 3 (3.0 mm/1.0 mm) 16.1 ◯ 22 1 (2.0 mm/2.0 mm) 48.3 Δ 23 160085.9  79 (3.95 mm/0.05 mm) 1.09 — 24 19 (3.8 mm/0.2 mm)  4.52 ⊚ 25 7(3.5 mm/0.5 mm) 12.3 ⊚ 26 3 (3.0 mm/1.0 mm) 28.6 Δ 27 1 (2.0 mm/2.0 mm)85.9 Δ 28 2000 134.2 Δ 29 8.0 500 11.2 19 (3.8 mm/0.2 mm)  0.59 Δ 30 7(3.5 mm/0.5 mm) 1.60 ◯ 31 3 (3.0 mm/1.0 mm) 3.73 ◯ 32 700 21.9 19 (3.8mm/0.2 mm)  1.15 ◯ 33 7 (3.5 mm/0.5 mm) 3.13 ⊚ 34 3 (3.0 mm/1.0 mm) 7.30⊚ 35 1200 64.4 19 (3.8 mm/0.2 mm)  3.39 ⊚ 36 7 (3.5 mm/0.5 mm) 9.20 ⊚ 373 (3.0 mm/1.0 mm) 21.5 ◯ 38 1600 114.5 19 (3.8 mm/0.2 mm)  6.03 ⊚ 39 7(3.5 mm/0.5 mm) 16.4 ⊚ 40 3 (3.0 mm/1.0 mm) 38.2 Δ 41 2000 179.0 X

As can be seen from Table 1, if the diameter (R1) and the speed ofrevolution (N) of the chemical agent retainer are set so that thecentrifugal effect (G) exerted on the chemical agent retainer fallswithin the range of 10 to 150 (m/s²), at least a predetermined level ofinsect killing effect is obtained. Furthermore, if the thickness ratio(P) is set to a value of more than 1.5 and not more than 50, and thecentrifugal vaporizing/discharging index (T) is set to a value of morethan 1.1 and less than 22, a more excellent insect killing effect isobtained. In contrast to this, if the thickness (B) of the chemicalagent retention layer is small, and the thickness ratio (P) is more than50, as in test nos. 18 and 23, the chemical agent retention capabilityof the chemical agent retainer is insufficient, and therefore, theexertion of the insect killing effect is likely to be impaired.Furthermore, if the thickness (A) of the gas permeable layer is small,and the thickness ratio (P) is not more than 1.5, as in test nos. 22 and27, a stirred air flow caused by the gas permeable layer is weak, andtherefore, the efficiency of vaporization and discharging of thevolatile chemical agent tends to be reduced.

Example 5

A hollow cylindrical chemical agent retainer retaining a volatilechemical agent was formed using a procedure similar to that of Example3, and was housed in a polycarbonate rotating cartridge similar to thatof Example 3. The rotating cartridge was coupled to a rotational drivepart. A chemical agent vaporizing/discharging device of Example 5 wasthus configured. In Example 5, a plurality of chemical agent retainershaving different inner diameter (R2) and different thickness ratios (P)of the gas permeable layer and the chemical agent retention layer wereprepared. By changing the speed of revolution (N), centrifugal effect(G), and centrifugal vaporizing/discharging index (T) of the chemicalagent retainer, differences in the effect of the volatile chemical agentwere studied (test nos. 42 to 81 in Table 2). A test method for theeffect verification test and a method for evaluating the insect killingeffect were similar to those of Example 4, except that the test wasconducted in a room having an area of 25 Jyos (105 m³).

TABLE 2 Diameter Speed of Centrifugal Thickness ratio (P): CentrifugalInsect Test (R2) revolution(N) effect (G) {gas permeable layer (A)/vaporizing/discharging killing no. (cm) (rpm) (m/s²) chemical agentretention layer (B)} index (T): (G/P) effect 42 6.0 500 8.4 X 43 70016.4 24 (4.8 mm/0.2 mm)  0.68 Δ 44 9 (4.5 mm/0.5 mm) 1.82 ◯ 45 4 (4.0mm/1.0 mm) 4.10 ◯ 46 1000 33.6 24 (4.8 mm/0.2 mm)  1.40 ◯ 47 9 (4.5mm/0.5 mm) 3.73 ⊚ 48 4 (4.0 mm/1 0 mm) 8.40 ⊚ 49 1400 65.8 24 (4.8mm/0.2 mm)  2.74 ⊚ 50 9 (4.5 mm/0.5 mm) 7.31 ⊚ 51  4 (4.0 mm/ 1.0 mm)16.5 ◯ 52 1800 108.7 24 (4.8 mm/0.2 mm)  4.53 ⊚ 53 9 (4.5 mm/0.5 mm)12.1 ⊚ 54  4 (4.0 mm/ 1.0 mm) 27.2 Δ 55 8.0 500 11.2 Δ 56 700 21.9 24(4.8 mm/0.2 mm)  0.91 Δ 57 9 (4.5 mm/0.5 mm) 2.43 ◯ 58 4 (4.0 mm/1.0 mm)5.48 ⊚ 59 1000 44.7  62 (4.92 mm/0.08 mm) 0.72 Δ 60 24 (4.8 mm/0.2 mm) 1.86 ⊚ 61 9 (4.5 mm/0.5 mm) 4.97 ⊚ 62 4 (4.0 mm/1.0 mm) 11.2 ◯ 63 1.5(3.0 mm/2.0 mm)  29.8 Δ 64 1400 87.7  62 (4.92 mm/0.08 mm) 1.41 Δ 65 24(4.8 mm/0.2 mm)  3.65 ⊚ 66 9 (4.5 mm/0.5 mm) 9.74 ⊚ 67 4 (4.0 mm/1.0 mm)21.9 ◯ 68 1.5 (3.0 mm/2.0 mm)  58.5 Δ 69 1800 145.0 Δ 70 10.0 500 14.024 (4.8 mm/0.2 mm)  0.58 Δ 71 9 (4.5 mm/0.5 mm) 1.56 ◯ 72 4 (4.0 mm/1.0mm) 3.50 ◯ 73 700 27.4 24 (4.8 mm/0.2 mm)  1.14 ◯ 74 9 (4.5 mm/0.5 mm)3.04 ⊚ 75 4 (4.0 mm/1.0 mm) 6.85 ⊚ 76 1000 55.9 24 (4.8 mm/0.2 mm)  2.33⊚ 77 9 (4.5 mm/0.5 mm) 6.21 ⊚ 78 1400 109.6 24 (4.8 mm/0.2 mm)  4.57 ⊚79 9 (4.5 mm/0.5 mm) 12.2 ⊚ 80 4 (4.0 mm/1.0 mm) 27.4 Δ 81 1800 181.2 X

As can be seen from Table 2, if the inner diameter (R2) and the speed ofrevolution (N) of the chemical agent retainer are set so that thecentrifugal effect (G) exerted on the chemical agent retainer fallswithin the range of 10 to 150 (m/s²), at least a predetermined level ofinsect killing effect is obtained. Furthermore, if the thickness ratio(P) is set to a value of more than 1.5 and not more than 50, and thecentrifugal vaporizing/discharging index (T) is set to a value of morethan 1.1 and less than 22, a more excellent insect killing effect isobtained. In contrast to this, if the thickness (B) of the chemicalagent retention layer is small, and the thickness ratio (P) is more than50, as in test nos. 59 and 64, the chemical agent retention capabilityof the chemical agent retainer is insufficient, and therefore, theexertion of the insect killing effect is likely to be impaired.Furthermore, if the thickness (A) of the gas permeable layer is small,and the thickness ratio (P) is not more than 1.5, as in test nos. 63 and68, a stirred air flow caused by the gas permeable layer is weak, andtherefore, the efficiency of vaporization and discharging of thevolatile chemical agent tends to be reduced.

INDUSTRIAL APPLICABILITY

The chemical agent vaporizing/discharging device and method of thepresent invention are used in order to repel or kill flying insect pestssuch as mosquitoes, black flies, nonbiting midges, flies, drain flies,clothes moths, and the like, and are also applicable to applications ofcontrolling creeping insect pests such as cockroaches, ants, centipedes,spiders, and the like.

REFERENCE SIGNS LIST

-   -   10 chemical agent retention layer    -   11 interstice    -   20 gas permeable layer    -   21 void    -   30 form maintenance layer    -   50 (51, 52) chemical agent retainer    -   60 rotational drive part    -   70 rotating cartridge    -   100, 200 chemical agent vaporizing/discharging device

The invention claimed is:
 1. A chemical agent vaporizing/dischargingdevice comprising: a chemical agent retainer having a chemical agentretention layer including interstices for allowing retention of avolatile chemical agent, and a gas permeable layer including voidshaving a size larger than a size of the interstices; and a rotationaldrive part for driving the chemical agent retainer, wherein a shape anda size of the chemical agent retainer, and a rotational speed of therotational drive part, are set so that a centrifugal effect of 10 to 150(G) is obtained during rotation of the chemical agent retainer, thechemical agent retainer is set so that the ratio (P=A/B) of a thickness(A) of the gas permeable layer to a thickness (B) of the chemical agentretention layer is not less than 3 and not more than 24, and therotational speed of the rotational drive part is set so that acentrifugal vaporizing/discharging index (T=G/P) obtained by dividingthe centrifugal effect (G) by the ratio (P) is not less than 1.14 andnot more than 21.9, the chemical agent retainer has a form maintenancelayer for maintaining a form of the gas permeable layer, the formmaintenance layer being disposed adjacent to the gas permeable layer,and the form maintenance layer is interwoven with fibers included in thegas permeable layer.
 2. The chemical agent vaporizing/discharging deviceaccording to claim 1, wherein the chemical agent retainer is a laminateof the chemical agent retention layer and the gas permeable layer, andthe chemical agent retention layer is provided one or both sides of thegas permeable layer in a lamination direction.
 3. The chemical agentvaporizing/discharging device according to claim 1, wherein the chemicalagent retainer is in the shape of a disc perpendicular to an axis ofrotation.
 4. The chemical agent vaporizing/discharging device accordingto claim 1, wherein the chemical agent retainer is in the shape of ahollow cylinder parallel to an axis of rotation.
 5. The chemical agentvaporizing/discharging device according to claim 1, wherein the chemicalagent retainer is housed in a rotating cartridge coupled to therotational drive part.
 6. The chemical agent vaporizing/dischargingdevice according to claim 1, wherein the volatile chemical agentcontains a pyrethroid compound having a vapor pressure of 2×10⁻⁴ to1×10⁻² mmHg at 30° C.